Some questions on recording area

[student]

Hi

Q1. I opened a window browser at the top left corner of my monitor and selected the area I want to record only the browser at top left, when I replay it I see black parts in the video of the unselected area of whole monitor (screenshot https://i.imgur.com/458Ep2V.png ), how to record without the black areas (only want to record selected area, not whole monitor with black areas) on my future video?

Q2. How to remove the black areas mentioned in Q1?

Q3. How to prevent recording the front and ending "showing I clicking the OBS software "start recording"/"stop recording" then I minimize it to taskbar" on my future video?

Q4. How to delete/remove (cut away) the front and ending "showing I clicking the OBS software "start recording"/"stop recording" then I minimize it to taskbar" on an existing video?

Q5. How to change from mkv to mp4? What is the difference of mkv vs mp4?

Thanks a lot

 

[WBE]

It appears that you are using a Display Capture source, which captures everything that is happening at that computer monitor including the OBS Studio. Please try to use a Window Capture source instead to only capture the browser window.

The source can be cropped: select it in the Sources list and have it unlocked (the lock icon is open). A red border appears around the source. Drag one of the little red squares while holding the Alt key down. For detailed cropping: right click the source, Transform, Edit Transform and adjust the settings.

OBS Studio is not a tool for editing existing video files. There are many... just do a little internet search. If you're looking for an easy way, you might consider Open Shot Video Editor. More capabilities, but also a steeper learning curve, come with DaVinci Resolve.

The .mp4 file format might be better known, but has a major disadvantage: some crucial meta data will only be written to the video file when ending the recording. So if something crashes after an hour, you end up having nothing. While in the .mkv situation you'd still have ons hour or recording most of the times.
At OBS's main menu you can Remux Recordings to convert .mkv to .mp4 files.

OBS Studio wiki: Sources Guide

 

[student]

Thanks, I think I will stick with .mkv

Does .mkv auto save if suddenly OBS crash/hang/close or if my PC hang or blue screen? If during recording in .mkv for 60mins and it crashes, does it mean I will have 60mins of recording saved?

If during recording in .mkv for 60mins and there is not enough space on disk , what happens? Will it auto save 60mins and stop recording? Will it still continue to record until the point that I press stop recording, then it save first 60mins, or whole clip unsaved due to not enough space?

Any idea what is the file size of .mkv vs .mp4 for same duration and settings? I think I would need to convert .mkv to .mp4 to upload to youtube.

 

[koala]

If recording an mkv gets interrupted somehow, it will contain valid video data up to the interruption. This will also happen if the disk gets full - the recording will just end at that point, however OBS will probably not explicitly stop recording - it will just try to continue writing, although it cannot.
For the same settings and duration, the file size of mp4 and mkv is the same.